Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond the readOnly/openWorld/idempotent annotations, the description discloses commitment level (confirmed), pagination terminus (next_before null on last page), memo truncation cap (200 chars), latency (0.3-2 s), pricing and free-tier limits, distinct 422/503 error semantics with no-charge guarantees, and a prompt-injection warning on returned on-chain strings. This is unusually rich behavioral context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Purpose is front-loaded and every clause carries operational weight (errors, pricing, timing, injection warning) with no filler. It is dense to the point of being a compressed run-on of metadata, which slightly hurts scannability.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, the description needn't explain return fields, yet it still clarifies pagination terminus and memo truncation. Pricing, latency, failure semantics, and safety guidance are all covered, leaving nothing an agent needs in order to call it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the schema already documents limit, before, and address including the before/next_before paging relationship. The description adds the output-side detail that next_before is null on the last page, but nothing about parameter syntax beyond the schema, so the baseline 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('List the recent transaction signatures of a Solana address') and explicitly routes the agent to the sibling get_solana_transaction for single-transaction details. An agent can distinguish it from the other Solana read tools without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly names the alternative (get_solana_transaction) and the condition that selects it, which is more than most tools provide. It lacks an explicit 'when-not' for this tool itself (e.g. when to prefer get_solana_account or balance tools instead), so it falls short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.